Output apparatus

ABSTRACT

An output apparatus for receiving code data from a data source of a host computer and developing it into pattern data and outputting the data. The apparatus includes a pattern generator to generate pattern data; a memory to store the pattern data generated by the pattern generator and obtained in response to an output operation as a font cache; and a controller for controlling the memory such that when an amount of available memory is less than an amount sufficient to store data which is newly input and which has higher priority of storage than the pattern data stored in the cache, the stored pattern data is deleted and the newly input data is stored. An auxiliary character font, form data, or a macro instruction is used as data which is newly input. The pattern data of the font cache in the memory is deleted on the basis of the priority. The pattern data is a dot matrix font pattern which was developed from a nondot matrix font.

This application is a continuation of application Ser. No. 07/522,582,filed May 14, 1990, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an output apparatus for receiving codedata from a data source of a host computer or the like and developinginto pattern data and outputting.

2. Description of the Related Background Art

In a conventional printer for printing by a dot matrix, a character codeor the like which is output from a host computer or the like is input,pattern data corresponding to the character code is read out of acharacter pattern generator and developed as image data into a framememory or the like, and thereafter, the image data is output to arecording section of a printer and recorded onto a recording medium. Thecharacter pattern data stored in such a character pattern generator canbe mainly classified into the following three kinds.

1 A dot matrix pattern to express a character pattern (hereinafter,referred to as a dot matrix font)

2 A font in which an outline or stroke of a character is expressed bycoordinate points for an origin of the character (hereinafter, referredto as a vector font)

3 A font in which a dot matrix pattern is compressed by some compressingtechnique (for instance, run length or the like) and constructed(hereinafter, referred to as a compression font)

Among those font data, the dot matrix font can be easily patterndeveloped into a frame buffer. However, since it is unsuitable for amodification of a character or the like, the use of the vector fontwhich can easily cope with the rotation, enlargement, reduction, etc. ofa character has been increasing more and more. On the other hand, as aresolution of output apparatus becomes high, a font capacity increases.To cope with it, a compression font is used. Further, in recent years, amixed type in which the vector font and compression font are combinedhas been also proposed. Assuming that the above fonts are generallyreferred to as "nondot matrix type fonts", although the nondot matrixtype fonts have advantages which cannot be obtained by the dot matrixfont, they have a problem such that it takes a longer time to develop apattern into an image memory or the like as compared with the simple dotmatrix type font.

To solve such a problem, there is a font cache method. According to thefont cache method, when a nondot matrix type font is developed into animage buffer or the like, font data or the like whose use frequency ishigh is previously developed into the dot matrix type font and storedinto a cache memory (RAM), and when developing into image data, by usingthe pattern data, a whole processing speed is improved.

In a printer or the like having such a font cache, in association with avariation of a print output, before print data is output from a hostcomputer, font data, auxiliary font data, form data (pattern such as abackground of each page or the like), etc. which have previously beenformed by the user can be downloaded and registered. The downloaded datais ordinarily stored into a fixed area in the font cache. Therefore,even if the downloading function is not used, a size of font cache islimited. On the contrary, in spite of the fact that a font data amountin the font cache is small, an amount of font data or the like to bedownloaded is limited.

SUMMARY OF THE INVENTION

The present invention is made in consideration of the above conventionalexample and it is an object of the invention to provide an image outputapparatus in which an area is dynamically assured in a font cachememory, an area priority in the memory is given to data to bedownloaded, so that the memory can be efficiently used and a processingspeed of the whole apparatus can be raised.

In consideration of the above points, another object of the invention isto provide an image output apparatus for receiving code data from anexternal apparatus and developing into pattern data and outputting,wherein the output apparatus comprises: pattern generating means forgenerating the corresponding pattern data based on the code data;pattern memory means for storing the pattern data generated from thepattern generating means into a memory as a font cache; memory means forreceiving the data from the external apparatus and storing into thememory; and control means for controlling in a manner such that uponstorage by the memory means, when a residual amount in the memory isless than a capacity enough to store the data from the externalapparatus, the pattern data of the font cache is deleted and the data isstored.

Still another object of the invention is to provide an output apparatus(method) comprising: pattern generating means for generating patterndata; memory means for storing the pattern data generated by the patterngenerating means as a font cache; and control means for controlling in amanner such that when a residual amount of the memory means is less thana capacity enough to store the other data which is newly input and whosepriority regarding the storage is higher than the priority of thepattern data, the pattern data of the font cache is deleted and thenewly input data is stored.

Further another object of the invention is to provide an outputapparatus (method) comprising: memory means for storing pattern data asa font cache; discriminating means for discriminating whether a capacityenough to store data which is newly input and whose priority regardingthe storage is higher than the priority of the pattern data can beobtained in the memory means by deleting at least a part of the patterndata or not; and storage control means for deleting the pattern data inaccordance with a predetermined priority in the case where it isdetermined by the discriminating means that such a capacity can beobtained.

Further another object of the invention is to provide an outputapparatus (method) comprising: memory means for storing pattern data asa font cache and storing data whose priority regarding the storage ishigher than the priority of the pattern data; discriminating means fordiscriminating whether an instruction to delete at least a part of thedata stored in the memory means has been input or not; and control meansfor controlling the memory means in order to expand an area to store thepattern data in the case where it is determined by the discriminatingmeans that such an instruction has been input.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a schematic construction of a controlsystem of a laser beam printer according to an embodiment;

FIG. 2 is a cross sectional view showing a construction of the laserbeam printer of the embodiment;

FIG. 3 is a diagram for explaining font data;

FIG. 3A is a diagram showing a character pattern shape;

FIG. 3B is a diagram showing dot matrix pattern data of FIG. 3A;

FIG. 3C is a diagram showing run length data of the pattern data of FIG.3B;

FIG. 4 is a diagram showing an example of a transmission format ofauxiliary font data from a host computer;

FIG. 5 is a diagram showing an example of a transmission format of formdata from the host computer;

FIG. 6 is a diagram showing an example of a transmission format of macroinstruction data from the host computer;

FIG. 7 is a diagram for explaining a used memory space in a memory;

FIG. 8 is a flowchart showing a registering process of data from thehost computer; and

FIG. 9 is a flowchart showing a font caching process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will be described indetail hereinbelow with reference to the drawings. The invention can beembodied in one apparatus or may be also embodied in a system comprisinga plurality of apparatuses.

[Explanation of the laser beam printer (FIG. 2)]

Prior to explaining a construction of the embodiment, a construction ofa laser beam printer to which the embodiment is applied will be firstdescribed with reference to FIG. 2.

FIG. 2 is a cross sectional view showing an internal structure of thelaser beam printer (hereinafter, abbreviated to LBP) of the embodiment.The LBP can register character patterns from a data source (not shown)and can also register a standard format (from data) and the like.

In the diagram, reference numeral 100 denotes an LBP main body forreceiving and storing character data (character code), form data, amacro instruction (an instruction to register a series of command groupsin a lump), etc. which are supplied from a host computer (201 in FIG. 1)connected to the outside. The LBP main body 100 makes the correspondingcharacter pattern, form pattern, or the like in accordance with thosedata and forms an image onto a recording paper as a recording medium.Reference numeral 300 denotes an operation panel in which switches foroperation, an LED display, and the like are arranged. Reference numeral101 indicates a printer control unit for controlling the whole LBP 100and analyzing character data or the like which is supplied from the hostcomputer. The printer control unit 101 mainly converts character datainto a video signal of the corresponding character pattern and outputsto a laser driver 102.

The laser driver 102 is a circuit to drive a semiconductor laser 103 andon/off switches a laser beam 104 which is generated from thesemiconductor laser 103 in accordance with an input video signal. Thelaser beam 104 is oscillated to the right and left by a rotarypolyhedron 105 and scans on an electrostatic drum 106. Thus, anelectrostatic latent image of a character pattern is formed on the drum106. The latent image is developed by a developing unit 107 arrangedaround the drum 106 and, thereafter, it is copy transferred onto therecording paper. A cut sheet is used as a recording paper. The cut sheetrecording papers are enclosed in a paper cassette 108 attached to theLBP 100 and are taken into the apparatus by a paper feed roller 109 andconveying rollers 110 and 111 and are fed to the drum 106.

[Description of the control system of the printer (FIG. 1)]

FIG. 1 is a block diagram showing a schematic construction of a controlsystem of the laser beam printer shown in FIG. 2.

The control system of the LBP receives character codes sent from thehost computer 201 as a generating source of print data and data 121comprising an auxiliary character font (for instance, a download font),form data, macro registration data, etc. and controls so as to printdocument data or the like on a page unit basis. Reference numeral 202denotes an input interface section to input various data from the hostcomputer 201; 203 indicates an input buffer to temporarily store thevarious data which were input through the input interface section 202;and 204 a character pattern generator. The generator 204 includes a ROMin which pattern data corresponding to character codes which werecompressed by, for instance, a run length method, ordinary charactercodes, and the like are stored, a read control circuit of the ROM, andthe like. The generator 204 also has a code converting function suchthat when a character code is input, an address of the character patterncorresponding to the input character code is calculated.

Reference numeral 205 denotes a RAM including a font cache area 207 tostore character patterns which were output from the character patterngenerator 204 and a storage area 206 to store an auxiliary characterfont, form data, etc. which were sent from the host computer 201. Asmentioned above, by storing the pattern data which was once developed tothe character pattern into the font cache area 207 as a font cache, whenthe same character is printed, there is no need to again decode the samecharacter and to develop the pattern. Thus, a developing speed to thecharacter pattern becomes fast.

Reference numeral 208 denotes a CPU to control the whole control systemof the printer. The CPU 208 controls the whole apparatus by a controlprogram of the CPU 208 stored in the ROM 215. Reference numeral 209denotes a frame buffer in which the pattern data which was developed tothe character patterns is stored by an amount of at least one page incorrespondence to a print image. Reference numeral 210 denotes an outputinterface section for generating a video signal corresponding to thepattern data which was read out of the frame buffer 209 and executingthe interface control between the output interface section 210 and apage printer printing device 211. Reference numeral 211 denotes theprinting mechanism section of a page printer for receiving the videosignal from the output interface section 210 and printing image databased on the video signal.

[Description of the font data (FIG. 3)]

FIG. 3 is a diagram for explaining the difference between a dot matrixfont and a nondot matrix font. FIG. 3A is a diagram visually showing anoriginal dot pattern (32×32 dots) which is not processed yet. A "*"portion indicates a portion in which an image is formed in black. FIG.3B shows data in the case where the dot pattern of FIG. 3A was expressedby hexadecimal data. Data of the portion which is printed in blackindicates "1" and data of the dot portion which is not printed is shownby "0". The dot pattern shown in FIG. 3B is constructed by 128 bytes andcorresponds to the image data which is stored into the font cache 207and frame buffer 209.

FIG. 3C shows data in the case where the dot pattern data of FIG. 3B wascompressed by using the run length. The pattern data of 128 bytes iscompressed into the data of 38 bytes. The run length method will now bedescribed hereinbelow.

1 A unit of each code is set to four bits.

2 A delimiter code E (hexadecimal number) is provided on each horizontaldirection (scanning direction) unit.

3 The code E further indicates that in one scan, all of the bits afterthe code E are set to "0".

4 The same scan data as the just preceding scan data is expressed by acode F (hexadecimal number).

5 Each of the code units (each consisting of four bits) in one scan isexpressed in accordance with the order of white and black and isrepeated hereinafter.

6 However, when the length is 13 or more, each code unit is expressed bythe sum of a code D (hexadecimal number) and one code unit (four bits)subsequent thereto. That is, the length is expressed by eight bits inonly the above case.

A numeral surrounded by ∘ in FIG. 3C indicates the scan number in amanner similar to FIG. 3A. For instance, the content "8464E" of the 14thscan shows that "from the left side, 8 bits are set to white, 4 bits areset to black, 6 bits are set to white, 4 bits are set to black, and allof the subsequent bits are set to white". On the other hand, the content"44D14E" of the 24th scan denotes that "from the left side, 4 bits areset to white, 4 bits are set to black, 14 (13+1) bits are set to white,4 bits are set to black, and all of the subsequent bits of the 24th scanare set to white".

By using the above rule, the character pattern of 128 bytes which areexpressed by FIG. 3B is compressed to the data of 32 bytes. In theembodiment, the font data stored in the character pattern generator 204is set to the compressed nondot matrix font as shown in FIG. 3C.

[Description of the data format from the host computer 201 (FIGS. 4 to6)]

FIG. 4 is a diagram showing an example of a data format of auxiliarycharacter font registration data which is output from the host computer201 when an auxiliary character font is stored into the storage area 206in the RAM 205. The format data is input through the input interfacesection 202 and is temporarily held in the input buffer memory 203.

In FIG. 4, reference numeral 401 denotes an auxiliary character startcommand to indicate that the subsequent data is the registration data ofthe auxiliary character font; 402 a parameter having a fixed length offour bytes indicative of the number of characters which are registeredas an auxiliary character font; 403 a character code which is assignedto the auxiliary character pattern; and 404 pattern data correspondingto code "1". In this case, total n character patterns are stored. Thecharacter pattern is set to a fixed length of 32×32 dots. That is, alength of character pattern "1" is set to a fixed length of 128 bytes.On the other hand, it is assumed that the auxiliary character font inthe embodiment is set to a dot matrix pattern as shown in FIG. 3B.

FIG. 5 is a diagram showing an example of a format of form registrationdata. In a manner similar to the foregoing auxiliary characterregistration data, form registration data is output from the hostcomputer 201 and stored into the input buffer memory 203.

Reference numeral 501 denotes a start command to indicate that thesubsequent data is the form registration data; 502 a parameter having afixed length indicative of the total number of bytes of the data to beregistered as a form; and 503 a data area of the form data as it is.Those form data may be also input from an ROM cassette or the like (notshown) and copied into the RAM.

FIG. 6 is a diagram showing an example of a data format when macroregistration data is input from the host computer 201. Reference numeral601 denotes a macro start command; 602 a parameter having a fixed lengthof four bytes indicative of a length of subsequent macro data; and 603macro data to be registered.

When at least one of the above data is sent from the host computer 201,the data is stored into the storage area 206 in the RAM 205 and is usedfor the subsequent print control.

[Description of the use state of the RAM 205 (FIG. 7)]

FIG. 7 is a diagram for explaining the use state of the memory 205.

In the diagram, reference numeral 701 denotes a memory map of eachconstruction of the whole apparatus when it is seen from the side of theCPU 208. The memory map 701 has a memory space of 16 Mbytes as a whole.A memory space assigned to the font cache area 207 and storage area 206is set to a memory space of 1 Mbytes from address "300000H" (H denotesthe hexadecimal number) to address "3FFFFFH". Reference numerals 702 to709 time sequentially indicate use states of the memory space in thememory 205.

Reference numeral 702 denotes the use state of the memory 205 just afterthe power source of the apparatus was turned on, in which all of theareas have been cleared and are not used now. Reference numeral 703denotes the state in which print data had been sent from the hostcomputer 201 and the printing was executed. The font data which was usedto print is developed to the pattern and the dot matrix data is storedas a font cache (207). Reference numeral 704 denotes the state in whichthe printing was further executed and the capacity of the font cache wasenlarged. Although the capacity was set to 400 kbytes in the state of703, it is increased to 800 kbytes in the state of 704. The number ofbytes of the unused area at this time is set to 200 kbytes.

When the registration data as shown in any one of FIGS. 4 to 6 istransferred from the host computer 201 in the state of 704, since thepriority of the registration data which was transferred from the hostcomputer 201 is higher, the font cache is deleted to obtain an area tostore the registration data from the host computer 201. In this manner,the font cache is further reduced by 200 kbytes and the registrationdata from the host computer 201 occupies 400 kbytes as shown in thestate of 705.

As mentioned above, since the font cache exists to improve the wholeprint throughput, even if the capacity of the font cache is reduced, theprinting itself does not become impossible. Therefore, by payingattention to the fact that the significance of the data from the hostcomputer 201 is higher, the priority of the font cache is set to a lowpriority.

Reference numeral 706 denotes the state in which the font cache wasfurther automatically deleted. In the state of 706, the characters arecleared in accordance with a predetermined algorithm on the basis of ause frequency of the font data, an LRU (least recently used: the patternwhich was most recently used remains) system, or the like and the cachearea is reduced. Reference numeral 707 denotes the state in which thefont area was enlarged by printing further another form, printing acharacter of a large character size, or the like. However, in this caseas well, the capacity of the font cache is also limited such that theregistration data from the host computer 201 is not erased from thememory 205.

Reference numeral 708 denotes the state in which a part of theregistration data from the host computer 201 became unnecessary and aclearing instruction of such a partial data was input from the hostcomputer 201. For instance, assuming that macro instructions of Nos. 1to 8 have been registered, FIG. 7 shows the state in the case where aninstruction to clear (or rewrite) only the macro instructions Nos. 3 and5 was input. Due to this, all of the areas (400 kbytes) which have beenassured by the registration data from the host computer 201 are releasedand are set to the "not used" state. Thus, the area of the font cachecan be further expanded and the font cache increases as shown in thestate of 709.

[Registration of data from the host computer]

FIG. 8 is a flowchart showing a process to register data from the hostcomputer 201 in the printer of the embodiment. A control program toexecute the data registering process is stored in an ROM 215 in the CPU208.

When data from the host computer 201 is received, step S1 follows and acheck is made to see if any vacant area exists in the memory 205 or noton the basis of the number of characters and the total number of bytesof the reception data of the data format shown in FIGS. 4 to 6. If YES,step S5 follows. If NO, step S2 follows and a check is made to see if astorage area can be obtained by clearing the data in the font cache 207or not. If NO, step S3 follows and a "MEMORY OVER" error is displayedand the processing is finished or the processing routine is skipped. IfYES in step S2, step S4 follows.

In step S4, the data in the font cache 207 is deleted by only the amountof the lack of the capacity of the storage area 206 and step S5 follows.In step S5, the area necessary to store the data from the host computer201 is obtained in the memory 205. In step S6, the data from the hostcomputer 201 is transferred to the storage area 206 in the memory 205and registered.

[Description of the font caching process (FIG. 9)]

FIG. 9 is a flowchart showing a font caching process. A control programto execute the font caching process is stored in the ROM 215 and isexecuted when the character pattern corresponding to the character codeis not stored at present in the font cache 207. However, as described inthe states 707 and 708 in FIG. 7, for instance, in the case where adeletion instruction of the macro instruction is input, the area to bedeleted can be also assured as a cache area. Even in this case, there isa large possibility such that the result of the discrimination in stepS11 in FIG. 9 is YES.

First, in step S11, the total number of bytes of the relevant characterpattern data is obtained and a check is made to see if a vacant areasufficient to store such an amount of data exists in the memory 205 ornot. If YES, step S14 follows. Such a discrimination is syntheticallyexecuted on the basis of the character size, form, LRU, and the like. Ifno vacant area exists, step S12 follows and a check is made to see ifany font data having a lower priority exists in the font cache 207 ornot. If YES, step S13 follows and the font data of the lower priority isdeleted from the font cache 207.

In the next step S14, a capacity as much as the font data to be newlystored is obtained in the memory 205. In step S15, the font pattern datais developed in the memory 205 and set to the font cache 207. Thepattern data which is registered to the font cache 207 is the data whichwas converted from the nondot matrix form to the dot matrix pattern.

Although the embodiment has been described above with respect to thecase of an apparatus such as a laser beam printer to print, theinvention can be also applied to a display device such as a CRT todisplay a dot image or the like.

On the other hand, although the embodiment has been described withrespect to the case where the font data based on the run length methodwas used as nondot matrix type font data, the invention can be alsoapplied to other various font data such as outline font to store what iscalled outline coordinates, font data to store a stroke of character,font data formed by synthesizing a bush of Chinese character, and thelike.

Although the embodiment has been described in the case where the fontcache and data registration area were set into the RAM, they can be alsoreplaced by another memory medium (hard disk or the like). Further,although the embodiment has been described with respect to the casewhere data which is sent from the host computer 201 was set to theauxiliary character font, form data, and macro instruction, the storageform and execution form are not limited in particular. For instance, theexecution of macro instruction may be also nested.

On the other hand, form instructions can be stored by a group of forminstruction as it is, by a bit map memory as a whole, or by anintermediate storage system and are not limited to the form data of onepage. A nondot matrix type can be also obviously used as an auxiliarycharacter font.

As described above, according to the embodiment, there is an advantagesuch that the memory can be efficiently used by dynamically managing thearea to store the data from the host computer and the font cache.

In addition, when the data from the host computer does not exist, all ofthe storage areas in the memory can be used as a font cache. If the data(auxiliary character font, form data, macro instruction, or the like)from the host computer exists, by giving the higher priority to such adata, the storage area in the font cache is not limited.

As described above, according to the invention, there are advantagessuch that by dynamically obtaining a storage area in the font cachememory and giving the higher priority of the storage area in the memoryto the data which is down loaded, the memory can be efficiently used andthe processing speed of the whole apparatus can be made fast.

As described in detail above, according to the invention, it is possibleto provide an output apparatus (method) comprising: pattern generatingmeans for generating pattern data; memory means for storing the patterndata generated by the pattern generating means as a font cache; andcontrol means for controlling in a manner such that if a residual amountin the memory means is smaller than a capacity enough to store otherdata which is newly input and whose priority regarding the storage ishigher than the priority of the pattern data, the pattern data of thefont cache is deleted and the data which was newly input is stored.

As described in detail above, according to the invention, it is possibleto provide an output apparatus (method) comprising: memory means forstoring pattern data as a font cache; discriminating means fordiscriminating whether a capacity enough to store data which is newlyinput and whose priority regarding the storage is higher than thepriority of the pattern data can be obtained in the memory means bydeleting at least a part of the pattern data or not; and storage controlmeans for deleting the pattern data in accordance with a predeterminedpriority in the case where it is determined by the discriminating meansthat such a capacity can be obtained.

As described in detail above, according to the invention, it is possibleto provide an output apparatus (method) comprising: memory means forstoring pattern data as a font cache and for storing data whose priorityregarding the storage is higher than the priority of the pattern data;discriminating means for discriminating whether an instruction to deleteat least a part of the data stored in the memory means has been input ornot; and control means for controlling the memory means so as to expandan area for storage of the pattern data in the case where it isdetermined by the discriminating means that such a deletion instructionhas been input.

We claim:
 1. An output apparatus comprising:pattern generating means forgenerating pattern data; memory means having an area capable of storing,as a font cache, pattern data generated by said pattern generatingmeans; and control means for variably controlling the area capable ofstoring, as a font cache, the pattern data on the basis of input of datadifferent from the pattern data stored in the area as a font cache, thedifferent data having higher priority than the pattern data.
 2. Anapparatus according to claim 1, wherein said control means variablycontrols the area by deleting the pattern data from the area and storingthe newly input different data in the area.
 3. An apparatus according toclaim 1, wherein the different data comprises auxiliary character data,form data or macro data.
 4. An apparatus according to claim 1, whereinthe pattern data comprises a dot matrix font pattern which was generatedbased on a non-dot matrix font.
 5. An apparatus according to any ofclaims 3 or 4, wherein the different data is given by a host computer.6. An apparatus according to claim 4, wherein the non-dot matrix font isan outline font, stroke font or run-length compressed font.
 7. Anapparatus according to claim 1, wherein the pattern data is generatedbased on non-dot matrix data.
 8. An apparatus according to claim 1,further comprising a printer for printing the generated pattern data. 9.An apparatus according to claim 2 or 8, further comprising a hostcomputer for giving the different data to said apparatus.
 10. Anapparatus according to claim 1, further comprising a display fordisplaying the generated pattern data.
 11. A printer comprising:inputmeans for inputting data received from an external apparatus; generatingmeans for generating character pattern data on the basis of font data ofnon-dot form; first memory means for storing the character pattern datagenerated by said generating means; second memory means for storingprint data based on the character pattern data stored in said firstmemory means; print means for executing a printing operation based onthe print data stored in said second memory means; and registrationmeans for discriminating whether said first memory means has a vacantstorage area in the event that said input means inputs, from theexternal apparatus, data having a higher registration priority than thecharacter pattern data stored in said first memory means, and fordeleting the character pattern data stored in said first memory meansand registering the data input by said input means in response to adiscrimination that said first memory means has no vacant storage area.12. A printer according to claim 11, wherein the external apparatuscomprises a host computer.
 13. A printer according to claim 11, whereinthe non-dot form font data comprises outline font, stroke font orrun-length compressed data.
 14. A printer according to claim 11, whereinsaid first memory means comprises a cache memory.
 15. A printeraccording to claim 11, wherein said second memory means comprises aframe buffer.
 16. A printer according to claim 11, wherein said printmeans comprises a laser beam printer.
 17. A printer according to claim11, wherein the registered data comprises auxiliary font data, form dataor macro data.
 18. A printer according to claim 11, wherein saidregistration means determines whether the input data can be registeredby deleting the stored character pattern data and registers the inputdata in response to a determination that the input data can beregistered by deleting the stored character pattern data.
 19. A printeraccording to claim 18, wherein said registration means issues an alarmindicative of an error in response to a determination that the inputdata cannot be registered even by deleting the stored character patterndata.
 20. An output method using a memory having an area capable ofstoring pattern data generated as a font cache, said method comprisingthe steps of:generating pattern data; and variably controlling the areacapable of storing, as a font cache, the pattern data on the basis ofinput of data different from the pattern data stored in the area as afont cache, the different data having higher priority than the patterndata.
 21. A method according to claim 20, wherein said controlling stepincludes variably controlling the area by deleting the pattern data fromthe area and storing the different data newly input in the area.
 22. Amethod according to claim 20, wherein the different data comprisesauxiliary character data, form data or macro data.
 23. A methodaccording to claim 20, wherein the pattern data comprises a dot matrixfont pattern which was generated based on a non-dot matrix font.
 24. Amethod according to any of claims 22 or 23, wherein the different datais received from a host computer.
 25. A method according to claim 23,wherein the non-dot matrix font comprises an outline font, stroke fontor run-length compressed font.
 26. A method according to claim 20,wherein the pattern data is generated based on non-dot matrix data. 27.A method according to claim 20, further comprising the step of printingthe generated pattern data.
 28. A method according to claim 21 or 27,further comprising the step of receiving the different data from a hostcomputer.
 29. A method according to claim 20, further comprising thestep of displaying the generated pattern data.
 30. A printing methodusing:generating means for generating character pattern data on thebasis of font data of non-dot form; first memory means for storing thecharacter pattern data generated by the generating means; second memorymeans for storing print data based on the character pattern data storedin the first memory means; and print means for executing a printingoperation based on the print data stored in the second memory means,said method comprising the steps of: inputting data received from anexternal apparatus; and discriminating whether the first memory meanshas a vacant storage in the event that data having a higher registrationpriority than the stored character pattern data is input from theexternal apparatus in said inputting step and deleting the storedcharacter pattern data and registering the data input in said inputtingstep in response to a discrimination that the first memory means has novacant storage area.
 31. A method according to claim 30, wherein theexternal apparatus comprises a host computer.
 32. A method according toclaim 30, wherein the non-dot form font data comprises outline font,stroke font or run-length compressed data.
 33. A method according toclaim 30, wherein the first memory means comprises a cache memory.
 34. Amethod according to claim 30, wherein the second memory means comprisesa frame buffer.
 35. A method according to claim 30, wherein the printmeans comprises a laser beam printer.
 36. A method according to claim30, wherein the registered data comprises auxiliary font data, form dataor macro data.
 37. A method according to claim 30, wherein saidregistering includes determining whether the input data can beregistered by deleting the stored character pattern data, andregistering the input data in response to a determination that the inputdata can be registered by deleting the stored character pattern data.38. A method according to claim 37, wherein said registering issues analarm indicative of an error in response to a determination that theinput data cannot be registered even by deleting the stored characterpattern data.